Pocket shot separator



Oct. 4, 1960 I J. BRZESKI 2,954,843

POCKET SHOT SEPARATOR Filed July 11, 1957 2 Sheets-Sheet '1 SHOT AND AIR INVENTOR. Jerzy Brzeski ATTORNEY Filed July 11, 1957 2 Sheets-Sheet 2 INVENTOR.

Jerzy Brzeski AT TORNEY United States Patent 9 POCKET snor SEPARATOR Ierzy Brzeski, Glasgow, Scotland, assignor to The Babcock & Wilcox Company, New York, N.Y., a corporation of New York Filed July 11, 1957, Ser. No. 671,178

Claims priority, application Great Britain July '18, 1956 3 Claims. (Cl. 183-94) This invention relates to separators for separating solid particles from gaseous particle conveying medium and while of wider application, is of utility in connection with apparatus such as that described in the complete specification of British Patent No. 745,556 for cleaning the surfaces of heat exchange means. In the cleaning system described in the said specification, solid cleaning particles are showered upon heat exchange surfaces disposed in an upright heating gas-pass, are collected at the bottom of the pass and are elevated by a gaseous particle conveying medium for re-use, the particles being separated from the conveying medium by directing the medium and entrained particles within a separator towards an impact plate. Suitably, the particles are in the form of steel pellets or shot and cleaning systems of the nature indicated are frequently termed shot cleaning systems.

"In the operation of a shot cleaning system, considerable expense and inconvenience are liable to arise due to wear of parts of the pneumatic conveying system particularity at locations where change of direction of the particles occurs, and reduction of wear and facilities for replacement of parts liable to wear are matters of considerable importance.

The separator target plate is particularly prone to wear and, in addition, impact of the particles with the target plate tends to result indeterioration of the particles from the point of view of their cleaning action, due to breakage of particles. Separators in accordance with the invention enable breakage of the cleaning particles and wear in the separators due to the particles to be reduced. In a separator for separating solid particles from gas- "eous particle conveying medium according to the present invention a tubulous inlet to the separator is arranged to direct the conveying medium and particles upwardly from a location outside a pocket towards a closed end of the pocket which is adapted to eifect a reversal of particle flow and discharge of the particles downwardly from the pocket into a space within a particle receiving chamber. Preferably the extremity of the tubulous inlet is spaced from the inlet to the pocket.

The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:

7 Figure 1 is a sectional side elevation of a separator for separating solid particles from gaseous particle conveying medium;

Figure 2 is a front elevation of a separator similar to that of Figure l but having two inlets for entrained particles and conveying medium associated with respective pockets and particle outlets, and showing alternative arrangements of piping for conveying entrained particles to the separator; and

Figure 3 is a sectional side elevation of a modified form of separator.

' In Figure 1 a particle receiving chamber 1 is provided solid particles such as shot as indicated by the arrow 13. The bottom 10 of the chamber 1 is formed as a sloping floor and the tubular inlet 2 extends into the chamber 1 through the bottom 10 and terminates upwardly thereof. The tubular inlet 2 is disposed below a pocket 4 formed in the top of the chamber 1 and comprising a tube 3 open at its lower or inlet end and of large diameter relative to the tubular inlet 2. The tube 3 and attached to a flange 7 formed on the tube 3. The plate 6 is suitably formed of mild steel and is retained on the flange 7 by bolts (not shown) in order to facilitate replacement thereof. The inner or impact surface of the plate 6 is disposed normally or substantially normally to the longitudinal axis of the tubular inlet 2 and suitably is faced with resilient material 6 to reduce wear and deformation of the plate, for example, if the temperature to which the plate is subjected does not exceed 250 F., high latex rubber may be used as the resilient material.

The pocket 4 is disposed partly outside the chamber 1 with the tube 3 extending partly downwardly below and partly upwardly above the top of the chamber. The tube 3 is formed intermediate its ends with a flange 8 whereby the tube 3 is secured to the top of the chamber by bolts (not shown). I

The sloping floor 10 of the chamber 1 is downwardly inclined towards a downwardly inclined particle outlet 9 formed at one side of the chamber as a continuation of the slope of the floor 10. The tubular inlet 2 terminates above the floor 10 so that particles may move down the slope of the floor 10 and through the outlet 9 as is shown by the arrow '14 without obstructing the inlet 2.

The chamber 1 is provided with an upper outlet 11 for the outflow as shown by the arrow 5 of gaseous conveying medium such as air through an up wardly directed outlet passage 12 spaced sidewardly from and extending parallel to the tube 3 of the pocket 4.

In operation, conveying medium and entrained particles are discharged upwardly from the tubular inlet 2 at a location outside the pocket 4 into the pocket 4 where some of the particles impinge on the impact plate 6 so that the direction of flow of the particles is re.-

versed. As a result, the pocket 4 contains a mass of particles the kinetic energy of which is largely dissipated by collision between particles in the enclosed mass. Thus the velocity of particles reaching the target plate is low and erosion of the target plate is relatively slight. Moreover, the breakage of particles is minimized.

The conveying medium flows from the inlet 2 in a generally radially outward direction and the particles falling from the pocket 4 are thrown outwardly and fall to the bottom of the chamber onto the sloping floor 10. The particles falling to the floor 10 accumulate and pass down the inclined surface, without obstructing flow from the tubular inlet 2, to the particle outlet 9.

The conveying medium leaves the chamber through the upright outlet passage .12 and owing to a double flow reversal which takes place within the chamber due to upward flow into the pocket 4, downward flow therefrom and upward flow through the passage 12 the tendency for particles to be carried with the outflow of conveying medium is minimized.

It is found that excellent separation of particles from the conveying medium is obtained and the impact plate may readily be removed for inspection or replacement.

The chamber 1 may be adapted to serve as a storage hopper, in which case the particle outlet is suitably provided with a shut-off valve, of the nature disclosed, for

example, in British Patent No. 745,620. In operation, pellets may accumulate above the lower part of the inclined floor without obstructing the tubular inlet 2.

In an arrangement in. which the chamber is adapted to serve as a storage hopper it may have a plurality of tubular inlets arranged to'direct conveying medium and particles towards the closed ends of respective pockets.

Thus, in the arrangement shown inv Figure 2, upright tubular inlets 20 and 21 are arranged to discharge upwardly into a chamber within the casing 22 and into re spective pockets 23 and 24. The chamber is formed with an upright upwardly extending outlet 25 for the outflow of conveying fluid as shown by the arrow 37, and respective downwardly inclined particle outlets 26 and 27 for the outflow of streams of particles as shown by the arrows 39, 38; Alternatively, the chamber may be provided with a single particle outlet connected, for example, to particle distributing means.

Suitably, each tubular inlet is connected with mixing means for effecting entrainment of particles by conveying medium by a pipe extending upwardly and without bends from the mixingmeans to the tubular inlet. Thus in Figure '2 a pipe 28 extends upwardly without bends from mixing means 29 adapted for the admission of particles downwardly as shown by the arrow 36 and of conveying medium upwardly as shown by the arrow 35. Since there are no bends, wear on the pipe is minimized.

Alternatively, each tubular inlet may be connected with mixing means for effecting entrainment of particles by gaseous carrier medium by a pipe extending upwardly and with a single bend from the mixing means to the tubular inlet, which bend is readily replaceable.

Thus in Figure 2 mixing means 30 are adapted for the downward admission of particles as shown by the arrow 33 and for the admission of conveying medium as shown by the arrow 34 and have an outlet 29 for conveying medium and entrained particles. The outlet 29 is con nected to one end of a bent pipe 31 which is connected at its other end with a straight upright pipe 32 extending upwardly to the tubular inlet 21. With this arrangement, although wear will occur it will be mainly limited to the bend and the worn part may easily be replaced without disturbing the mixing means 30 or the pipe 32.

The arrangement using a. pipe without bends extending between mixing means and the tubular inlet to a particle separating chamber is advantageously employed when the mixing means may be disposed vertically below the separating means, whereas the arrangement utilizing a single bend is advantageously employedwhen the mixing means are spaced sidewardly from the separating means and the provision of a bend enables a straight upright duct to extend from the bend to the particle separator.

in the embodiment shown in Figure 3, the common axis of a tubular inlet 4%? and a particle receiving pocket 41 is inclined and the chamber 42 is formed with a lower downwardiy directed particle outlet 43 and an upper upwardly directed outlet 44 for conveying medium.- The chamber 42 is formed as upper and lower parts 45 and 46 of frustoconical form united at their wider ends by a cylindrical part 47, the outlets 43 and 44 andthe parts 45, 46 and 47 of the chamber 45 being coaxially arranged. In operation particles falling from the pocket 41 accumulate on a downwardly convergent floor to the chamber provided by the frusto-conical part 46 above the particle outlet 43.

The inclination of the tubular inlet 40 andtthe pocket 41 serves to obviate the need for bends in a. pipe extendrng from mixing means to the tubular inlet 40 where by :rnclining the inlet 45 and the associated mixing means a :straight pipe may extend therebetween.

Separators of the nature described are advantageously used in connection with particle scattering means disposed above heat exchange surfaces to be cleaned. In the case of a chamber adapted to serve as a storage hopper and fitted at its outlet with a shut-off valve, the discharge from .-the shut-off valve may be to ,a distributor for directing 4 particles through respective pipes to a plurality of particle scattering means disposed above the heat exchange surfaces to be cleaned. Alternatively, when the chamber is arranged to discharge the particles directly they are sepa-. rated, the chamber may be provided with a plurality of outlets leading through respective pipes to a plurality of scattering means disposed above the surfaces to be cleaned.

While in accordance with the provisions of the statutes 1 have illustrated and described herein the best form and mode of operation of the invention now known tome, those skilled in the art will understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by my claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

What is claimed is:

1. Apparatus for separating solid particles from gaseous particle conveying medium comprising walls defining a chamber having a gaseous conveying medium outlet in the upper portion and at least one solid particle outlet in the lower portion thereof, a tubular inlet pipe of substantially uniform cross-section flow area for the discharge therefrom of a mixture of solid particles and a gaseous conveying medium into said chamber, and a cylindrical member coaxial with said tubular inlet pipe and having a closed end and an open end, said open end being axially spaced from the discharge end of said inlet pipe within said chamber, said cylindrical member beingof increased cross-section as compared with the cross-section of said tubular inlet and having its closed end portion projecting beyond a wall of said chamber, said member being detachably secured to a wall of said chamber and defining a pocket to reverse the direction of movement of said solid particles and conveying'medium while in contact with a continually changing suspension mixture of said particles and medium to separate the particlesfromthe conveying medium.

2. Apparatus for separating solid particles from gaseous particle conveying medium comprising walls defining a chamber having a gaseous conveying medium outlet in the upper portion and at least one solid particle outlet in thelower portion thereof, a tubular inlet pipe of substantially uniformcross-section flow areafor the discharge therefrom of a mixture of solid particles and a gaseous conveying medium into said chamber, and a cylindrical member coaxial with said tubular inlet pipe and having a closed end and an open end,.said open end being axially spaced from the discharge end of said inlet pipe within said chamber, said closed end being replaceably secured to said cylindrical member, said cylindrical member being of increased cross-section as comparedwith the crosssection of said tubular inlet and having its closed end portion projecting beyond said chamber, said member being detachably secured to a wall of-said chamber and defining a pocket to reverse the .direction of movement .of.said solid particles and conveying medium while in contact with a continually changing suspension mixture of said particles and medium to separate the particles from the conveying medium. 7 a

3. Apparatus for separating solid particles from gaseous particle conveying medium comprising" walls'defining a chamber having a gaseous conveying medium .outlet in the upper portion and at least one solid particle outlet in the lower portion thereof, a-tubular inlet pipe of substantially uniform cross-section flow area for thedischarge therefrom of a mixture of solid particles. anda gaseous conveying medium into said chamber, and a. cylindrical member coaxial with said tubular inlet pipeand having a closed end and an open end, said open end being axially spaced from the discharge end of said inlet pipe-within said chamber, said closed end being replaceably secured ing ofgincreased cross-section as compared with the crosssection of said tubular inlet and having its closed upper end portion projecting beyond said chamber, said member being detachably secured to a wall of said chamber and defining a pocket to reverse the direction of movement of said solid particles and conveying medium while in contact with a continually changing suspension mixture of said particles and medium to separate the particles from the conveying medium.

References Cited in the file of this patent UNITED STATES PATENTS 293,445 Prick Feb. 12, 1884 2,172,133 Thuillard Sept. 5, 1939 2,626,141 Grossman Jan. 20, 1953 6 Kent Oct. 20, 1953 Bergstrom Jan. 19, 1954 Norris Mar. 16, 1954 Bergstrom Jan. 7, 1958 Drew Mar. 31, 1959 Bergstrom et al. Mar. 31, 1959 FOREIGN PATENTS Austria July 10, 1913 Great Britain Feb. 7, 1924 Great Britain J an. 14, 1941 Great Britain June 16, 1954 Germany Apr. 14, 1927 Belgium June 20, 1952 

